Xstrata will resume A$186m ($157m) of planned investment in exploration activities associated with its Rolleston West, SARUM and Wandoan coal projects in Queensland, Australia.

The company said the decision to recommence investment follows the federal government’s announcement that it proposes to replace the resource super profits tax with a mineral resource rent tax.

Meanwhile, Rio Tinto said it is restarting studies on its multibillion dollar Pilbara iron ore expansion after the recent mining tax deal.

The company wants to increase iron ore production to about 330 million tons a year from about 230 million tons by 2015.

Last week Australia agreed to cut the resource tax from 40% to 30% and include only coal and iron projects in the tax deal.